Revert 291221 "Athena: Adding basic resource management framewor..."

Revert 291221 "Athena: Adding basic resource management framewor..."

Reason: Failure on ASAN build bots.
https://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20(3)/builds/2854/steps/athena_unittests/logs/OneAppActivity

> Athena: Adding basic resource management framework (un-/re-loading) of V2 applications
> 
> Functionality:
> 
> The |AppRegistry| has for each running application an |AppActivityRegistry|.
> 
> The |AppActivityRegistry| knows all activities associated with the application it represents.
> It can furthermore shut the app entirely down upon resource manager request. It will then create
> an |AppActivityProxy| for the overview mode which shows a placeholder for an unloaded app. This
> placeholder can then ask the |AppActivityRegistry| to restart the application again.
> 
> A shutdown request for the application is only performed when all activities were marked for
> UNLOAD.
> 
> If there were multiple activities upon shutdown for one app, the app has to take care of
> re-creating all windows and thus re-creating all activities. Since an activity match cannot
> be performed, the |AppActivityProxy| will only be shown once and it will show in the location
> of the most recently used activity of that app. If we later on find an app which really uses
> multiple windows and it is imperative to keep the history for all of them tact & the app is
> recreating them properly, (a lot of if's) we can revisit the single |AppActivityProxy| and
> try to address it in a cleaner way, but at this time that seems rather un-useful since it is
> not known if required.
> 
> BUG=388085
> TEST=AppActivityTest.*
> 
> Review URL: https://codereview.chromium.org/477523002

TBR=skuhne@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=291370

[Finnur, 2014-08-22 10:21:26]

Committed patchset #1 manually as r291370.